Gate-first inversion-type InP metal-oxide-semiconductor field-effect transistors with atomic-layer-deposited Al2O3 gate dielectric

We present n-channel enhancement-mode inversion-type indium phosphide (InP) metal-oxide-semiconductor field-effect transistors with atomic-layer-deposited Al2O3 gate dielectric. It has been found that applying sulfur passivation and postdeposition annealing in the process improves the drive current and subthreshold swing. Transistors on semi-insulating InP substrates show much higher drive current than the ones on p-type InP due to the asymmetric distribution of interface state along the bandgap between InP and Al2O3. The effects of transient and slow traps on the transistor performance have also been investigated using constant electrical stress measurements and pulse measurements.